Messages in this thread | | | Subject | Re: [RFT PATCH 2/2] Revert "usb: dwc2: Fix probe problem on bcm2835" | From | Martin Sperl <> | Date | Sat, 19 Mar 2016 08:44:09 +0100 |
| |
> On 19.03.2016, at 03:17, Eric Anholt <eric@anholt.net> wrote: > > Stefan Wahren <stefan.wahren@i2se.com> writes: > >> Hi Eric, >> hi Martin, >> >>> John Youn <John.Youn@synopsys.com> hat am 16. März 2016 um 19:28 geschrieben: >>> >>> >>> On 3/10/2016 11:14 AM, John Youn wrote: >>>> On 3/9/2016 11:06 AM, Doug Anderson wrote: >>>>> >>>>> John: it's pretty clear that there's something taking almost exactly >>>>> 10ms on my system and almost exactly 50ms on Stefan's system. Is >>>>> there some register we could poll to see when this process is done? >>>>> ...or can we look at the dwc2 revision number / feature register and >>>>> detect how long to delay? >>>>>
Maybe this difference is related to overclocking settings in the firmware?
>>> >>> 1. What is the AHB Clock frequency? Is the AHB Clock gated during >>> Reset? > > Low confidence here as I'm tracing lines across a ton of modules, but it > looks like it comes from the USB AXI clock in peri_image, which is a > gate on the normal 250Mhz APB clock, but nothing should be touching that > gate register as part of USB reset as far as I know. > Isn’t it possible that this clock (probably BCM2835_CLOCK_VPU) is changed by the firmware due to overclocking settings in /boot/config.txt?
Martin
| |